why cant trains get a more efficient emergency brake system?
One of the reasons that trains are so efficient (in fuel used per kilo of cargo) is that their wheels don't have much rolling resistance. So you can't use car-type brakes very efficiently – there just isn't that much grip between the wheels and the track. Another reason, relevant for passenger tr…
The Short Answer
One of the reasons that trains are so efficient (in fuel used per kilo of cargo) is that their wheels don't have much rolling resistance. So you can't use car-type brakes very efficiently – there just isn't that much grip between the wheels and the track. Another reason, relevant for passenger trains, is that the people inside are not strapped in, the luggage is not secured, people are walking around, etc. Instead of making sure trains *can* stop very quickly and managing traffic with that in mind, it's better to manage traffic so that trains *don't have to* stop very quickly.
Analysis
Key Concepts: Trains, wheels, don't
This explanation focuses on trains, wheels, don't and spans 101 words across 4 sentences. At 42% above the average Nature explanation (71 words), this is one of the more thorough answers in this category, reflecting the complexity of the underlying question.
What This Answer Covers
The explanation opens with: “One of the reasons that trains are so efficient (in fuel used per kilo of cargo) is that their wheels don't have much ro” It then elaboratesultimately building toward a complete picture across 4 connected points.
How This Compares in Nature
Ranked #117 of 500 Nature questions by answer depth (top 24%). This places it in the comprehensive tier — the top quarter of most thoroughly answered questions. Questions at this depth typically involve multi-faceted topics requiring nuanced explanation.
Frequently Asked Questions
Is there a simple explanation for why why cant trains get a more efficient emergency brake system?
One of the reasons that trains are so efficient (in fuel used per kilo of cargo) is that their wheels don't have much rolling resistance. So you can't use car-type brakes very efficiently – there just isn't that much grip between the wheels and the…
How detailed is this explanation compared to similar Nature questions?
This is one of the most thorough answer at 101 words, ranked #117 of 500 Nature questions by depth. The key concepts covered are trains, wheels, don't.
What approach does this answer take to explain why cant trains get a more efficient emergency brake system?
The explanation uses root cause analysis across 101 words. It is categorized under Nature and addresses the question through 1 analytical lens.